What is the most interesting team sport?

What is the most interesting team sport? We answer this question via an extensive statistical survey of game scores, consisting of more than 1/4 million games in over a century. We propose the likelihood of upsets as a measure of competitiveness. We demonstrate the utility of this measure via a comparative analysis of several popular team sports including soccer, baseball, hockey, basketball, and football. We also develop a mathematical model, in which the stronger team is favored to win a game. This model allows to us conveniently estimate the likelihood of upsets from the more easily-accessible standings data.